Finite Element Calculation of Normal Electromagnetic Force at Feature Key-points of Permanent-magnet Synchronous Motor

Under the action of too large electromagnetic force, the structure fault of permanent magnet synchronous motor may occur. In this study, a mathematical model of permanent magnet synchronous motor which combines a two-dimensional magnetic field-path coupled finite element method with Maxwell's stress method was proposed first. Then, the harmonic decomposition graph and distribution of harmonic content of normal magnetic flux density were obtained by analyzing the magnetic flux density change characteristics at the key points. Finally, the variations of the normal electromagnetic force at feature key points were calculated. The calculation results show that the change rule of magnetic flux density is related to the feature key-point; the 13 times harmonic content at feature key-point should be attached with high attention, which provides theoretical support for studying vibration characteristics of motor structure.